1. Field of the Invention
The present invention generally relates to a conformable self sealing seal for the cables entering an end of a closure for a cable splice or termination, and in one aspect to an improved environmental seal to restrict migration of fluids into or out of a closure.
2. Description of the Prior Art
The prior art related to end seals for splice closures for cable splice closures or terminations is replete with systems for fitting a variety of wire or cable diameters and a variety of closure ends. One of these end seals is described in U.S. Pat. No. 4,902,855 and assigned to the assignee of the present application. This end seal comprises a foam collar which is fitted about the cable or cables and an annular ring is placed about the collar and it is cut to fit about a cable on a finished splice, and the ring has a cut which joins the inner opening to the outer periphery and along a path which is tangential to the inner opening.
U.S. Pat. No. 4,963,698 describes a sealed cable article and method for sealing the area between two cables and an enclosure where the cables exit from the closure. The article comprises a shaped article of polymeric gel having a cone penetration value of about 30 to about 400 (10.sup.-1 mm) and an elongation of from 25% to about 850%. The gels are widely known in the art, for example silicone-based gels, polyurethane-based gels or polystyrenebutadienestyrene, polystyrene-isoprene-styrene, and polystyrene-ethylene butylene-styrene block copolymer based gels. The inventors preferred gelloid compositions comprising a crosslinked non-silicone polymer having an olefinic unsaturated content of less than 10 mole percent and having dispersed therein a liquid in an amount of from about 20% to about 95% by weight based on the weight of the liquid and polymer and from 0 to 0.3 volume fraction of a filler. The shaped article preferably has a number of holes preferably slightly smaller than the size of the cables. The gel will stretch to accommodate the increased size cables. There is a slit extending from the edge of each hole to the outer edge of the article so that the shaped article may be placed around the cables without access to the free end of the cable. FIGS. 4, 5 and 6 illustrate the shapes of the article.
Articles of a similar shape are illustrated in French patent 1,168,267, in FIGS. 18, 19 and 20. PCT application WO 90/05401, published May 17, 1990 also discloses an end seal to fit about a plurality of cables and which is made of a gel, i.e. a liquid-extended polymer composition preferably having a cone penetration value within the range from 30 to 400 (10.sup.-1 millimeters), an ultimate elongation greater than 100%, with substantially elastic deformation to an elongation of at least 100%. The composition may either contain three-dimensional cross-linked molecular formations or may merely behave as if it contained such molecular formations (gelloids). Specific examples and preferred properties are disclosed and on page 12 there is a teaching that the gel may include a tackifier which helps adhesion of the gel to the substrate and also to itself.
These references of prior art end closures do not disclose an end seal article which is capable of sealing a variety of cable and wire sizes to a closure, or closures of different diameters, and which comprises a core portion with a plurality of openings communicating with the outer periphery and a wrap-around tail portion which is adapted to make at least one complete wrap about the periphery of the core portion to seal between the cables and about the cables to the inner surface of the closure.